This time around, Facebook may actually have seen its privacy Watergate: A report in The Wall Street Journal on Monday found that the phenomenal amount of personal information that Facebook members put in their profiles may indeed have been sold extensively to marketers, advertisers, and data collectors. The big question, appropriately enough, is what Facebook knew and when did it know it.

Here's what happened: When Facebook members agree to connect their Facebook credentials to any of the hundreds of thousands of applications that implement its third-party developer application programming interface (API), they are giving those developers access to their Facebook member ID numbers and in turn all publicly available information about them on Facebook (which includes names and lists of friends). The problem, according to the Journal, is that some of these third-party companies, including extremely popular ones like FarmVille manufacturer Zynga, were selling that data to advertisers and tracking companies in violation of Facebook's terms of use. Some of those tracking companies, too, were matching up Facebook user data to other personally identifying information that they had on hand, in effect putting together puzzle pieces into clear pictures of unsuspecting users' identities.

Thus, beyond the "What did Facebook know?" question comes the accompanying concern that the company's powerful development platform has gotten so big that Facebook can no longer wrangle it.

It's no secret that the initial explosion of apps on the platform, well over three years ago, was what gave Facebook its first big "kick" as a major power in Silicon Valley. The expansion of the platform into Facebook Connect, one data firm said, was what ultimately pushed it past MySpace in U.S. traffic. Some of the most prominent Facebook app manufacturers were making a profit before Facebook was, and at one point a third-party assessment concluded that the platform was a bigger business than Facebook itself. So, in short, Facebook owes a lot to the success of third-party apps, and those apps in turn can credit much of their success to the fact that they've been able to build on top of Facebook's powerful grid of connections.